SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c6448a6dba4c52b8a6665ede8f95ed066112f5d0d276e36fc1dc935dbeee133' 
  AND token = 'QUpai5fjWLm4JF2+tOkhmDO9e5cIxbF0gZqDR0AAazk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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