SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43c405dd35308799c3d5cdbc0727ea41a82080664a357e0023a505c70638a775' 
  AND token = '1ghHsUeaLFRfkOaQYv1oHGnPLrDmklp+7eqJ0v+q5wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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