SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3dcfb8276946cc2c88bc9e15ff6c6ba07248f272e336e8f7ad5f1503f07e027' 
  AND token = 'nuAVuyK4bKWcn2BLumTTeyg7flLRW4Q8NK+zfCZKtCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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