SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25eb33535518f47b26e2c5c9b76abca11c18af8293d0855383f9600d56f7b55e' 
  AND token = 'zrUG1Tgs48sh6XL3yuyfVVBJyoeFNdW4ZP3mK3Y8dp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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