SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0041d4948e3948b712a820e84c517fe1f9cd196fa5c30ee540da5b241489a3c5' 
  AND token = 'i3rI82C3S7t9ZYV8PMGU4EC68t3sk7QU7Q8VydoiejU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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