SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f37f4bcb50fcf35cbdb3724cd72f284ac7e62edb7cbd95ca79139e24406b25b' 
  AND token = '6kxm9rfGi3x0RsuGChNajQlZsYDd4k+lrenC/c32aqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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