SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e624e57ced66f9ee10a9745fb98b07183b2df3230ab71305ea1c5d77a5f9255' 
  AND token = 'RIVULdJ5S+rF+wV+jV+xQPSV1s/rPSUhgJztIhh3tMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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