SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ac2539b5204d1d2f4e4d76f3aef33877d405bcaf209c5bf53313bdda8814536' 
  AND token = 'SwZy6dxgdOSPmAg0hcdCzHRuR9VDXfArdvI71HMbWJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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