SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a072a0a205a88e474d1019637bbafb11643fc7736b9642fc5ec4b1b478c6e97' 
  AND token = 'Z7w3eCkPkrN8afmNy1zlKa/xk7Frdg624h5AZd8vEuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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