SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e04a5956a5adea943b703f5ccddbccd73f2062f1f5a07eec46bd72b246d36243' 
  AND token = 'QkeRT/DXLJ3Cga5Kw4S/t6HmGl6vDmErB8UZezVJsCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}