SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87d564ac5563a209e1068d5cf7ae1d05bcfa67e74187ab84ed5926133d01de78' 
  AND token = 'rnr4yp4yMCZfltwf9DrLFhX7YKlzYlA63kLg/gNb5AI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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