SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7581eab5db0b78fc1651c1903da63946872c5a05fc09cfc8374f19fc7ed932bb' 
  AND token = '/G8DHjMOPES4KpiIWDSFly/EAHJznCRC/n1gIlLQ0Rw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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