SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dd1486713687c4d65a436a5265c59dd3f887e134e848671d875daa2b11311dc' 
  AND token = 'TCaIGpeLD25z0UXldnOWSO1mPfEMNct853+y8esMGPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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