SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bb2ccd0a2192b4ab631a09316f8eb1792a12fef33f62f7ceda9e336668b7bc2' 
  AND token = 'EfcF7tLjT08vkI6svfX2Z335TGZRMP9GBAVDu7/GkgI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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