SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54f6226008c9bbcaff7f1c56315fa84d79864c6d7da43f815027607b9b0db9c7' 
  AND token = 'W6fFy/KzdYlCFBlE3cgB3ZQJF4/D+jdXTfY8qClc7CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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