SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e297749322a1b88f1ce0a482bdd191f5cdaf4bfa6a9b760914d6cf0321bf4b62' 
  AND token = 'Y3fgtNcR0TVumRXQLTc4Jfjmu00nO2ZwXAWPWkKVRJ0=' 
  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"
    }
  }
}