SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b655273330dd4cf86c620526e9ce7e03847e89f8012f0045f773fbcba09f3f6' 
  AND token = '3sAWKgwXJouw17m8ODcBZ78EmnTL9M0Ce9iuAcedCys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}