SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17571a0591efecfbfbbc342f8119ffffbb94f5e892b2040de1a2668372a95674' 
  AND token = 'Cnl1fgymVDCJ37IqE7aEX+aMrW548W1dDfR203xX74o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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