SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c273e0e2ad98b4c83aa1c0af5b73e6a31f2ddcdd04b8fd8363a882eccc24758' 
  AND token = 'EQbSUB7FX5i27WrBIyAtZ66u5SDLdEfVYf7nDuYWNA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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