SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67dbd0835214cdb2b0d5c3892bc1be8398d83885cfbd465055d4316529614ea0' 
  AND token = 'LxY4okrs9F7w3Jfhz69ocI96x+G4geJyF0cWh8iyDvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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