SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be4c8ad29fc80321fec7c7af427665473129873f6bf9e0f3b982f3f65c01b898' 
  AND token = 'ObfY+T1f8yG20PSRJuETiffpEMcomfECRoGJCpY6sW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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