SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '661ddc38fa20197e375fceba5479fd207a96c8aed88a2b8e0bbc9e0a022f82cf' 
  AND token = 'G7eO/Pl6JVSQPqx3IsABiJLuEPuSmSMHOUyufX2B9MM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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