SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9826fe9524a60595d0c3a60c2fcab12ca56ceb8a16cc911f8c83a2c350adc395' 
  AND token = 'EjMzHgW4c+318iMmHnKuVP8PTR2lfPm2QapEVp1QsQc=' 
  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"
    }
  }
}