SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '889c43bee97beb059d207707050cf1a51a12ff6174610bbc4a6e7c1087eb22e3' 
  AND token = '4T5Glc5gqd7bY5M83kNo6Fy8GFbhr1kICHC52PsmsEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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