SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce14c862bc8becd0e9e275fac720c251ab72144022a3bfd0aaeca9063219e688' 
  AND token = 'kAe++Dq9E1Jgjj/LYBYiARsXaUM39v3Yk+k1l4hDob8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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