SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5689c2a71ae5c04dd7a2025d600e77b7c36e29647d29aacd554191473165882f' 
  AND token = 'flG8/ZAt7HbvImn/mASW8pHjtVpElZr1IE/+DuR/vfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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