SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '144778f6e7815d8a90b7477b21afaaff98a36dc7876de111f18bf785dc4d77a1' 
  AND token = '8+Lw/uYjeMrnBlSQzENu4Ef+ZTemXeEJpps2sN9LzSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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