SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3e25fb11107cc5bd7fc1246b6d4743825a7bc4a782790fc96937b42c59ea6c3' 
  AND token = 'd6FuqqlPWI/K4rdTGywW5/BLcZ5PvlquLH83SXkKdUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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