SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd6fbab887450a65512dee3a46cccaf657dcf7b50446df59870c099c91041843' 
  AND token = 'PTg61XyuVhuawKyuXp869wfA1Fn0jwCqRnrcphwrJeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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