SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c15d23f64d043bbe8a6c1cd114e51c20b36e2758171f4fd6b99988436dab70eb' 
  AND token = 'GXy7FKU512jicp3oxwXVYlFvbqup49F2Rwu9EqnpNQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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