SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7b1b5561589f08e3e309b4db56b2f364a9d36647447a7caad410c4731a4f96f' 
  AND token = 'ELUbJ9oaslzgRQ5XSme0y11b3dg0N5TCDtP5Pzwygis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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