SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f1d2362d8a0947fe73e8b29731646a3f991eee2a3fda5996f5bba17b03123411' 
  AND token = '85YvfRSG66m95ZJp5CRrjr1VbK5y9wVWmHsliLbN5lA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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