SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cff17c76318f7515d2be91442190589d20cd64bccbdd0e4e16bb9575175a8d55' 
  AND token = '3+/BIty352rXXuZrsLARiUtWc2LeNvy9ll9xzb71j2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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