SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b362699e51e0bc0afefb55602668c6f3f34687fd1f34df480facc2a5a8f834b9' 
  AND token = 'NQq8Zh2k6nc/KiBzJZKMpohvJ0FxoJumuM/Hzdub1QY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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