SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8c9b359f51a4128988eaecc56542987c6253745f0f7f90f4900798c5191381eb' 
  AND token = 'VlxrU2K/thh2d0810CurnKsQg4+hK3gZDbqoUJ3rFkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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