SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1702143d31d701a32736f36f6db252aa1e917f01bd309fce6d4fc2b7f01fa35f' 
  AND token = '4UwdRaSjjNXMGlQFRu/4nGNXyRTAuw2LuEFeBMoiiho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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