SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fbbbf26dfd46699094c1eb2aa1fddfce404be4b415e6aba8d69694d5610ad3d' 
  AND token = 'thxlF/9RTR+x1ISFubFLdkaGqX0CcjnVv6IMH5B/eUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}