SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44324c2efecfece5361617c98f16af1b0306bb1448549cd97b15e817314661da' 
  AND token = 'ZxfF0K4SzshB5+ijBMpwFAUmmdir59rFhXzbDt64KLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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