SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b770a5f74a0b87bfb0b9ce90e6199327d78b72acd356aced01741c9415122731' 
  AND token = 'goR7QQlZPMC+T9ulATrxIAtqzoHGnz0GyABFo91DfRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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