SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f00148610882dbf8df21fb8f139217974597edea6eb167882051317d4971f6ae' 
  AND token = 'urIDlvsFITgpSXEJhItCx4/rOPo1Mnn/796Osemt48s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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