SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '548dc1886414b52a8239f36c97a81e4d98580e0cd7db4a888af1e4686029bf93' 
  AND token = '4zjug0wigyZ4wPMfArtWY2WirgYcx+6mjdM3A3EU1Yg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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