SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f99ed2dbef51b7073bed5a1466005246cdebd50da6286cc42cec845e6e6f9470' 
  AND token = 'NGnsY+iCKIoNmR1qAJNHe5OXR0Wjrr63cbhwwhftSUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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