SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ead584d32e8544d51a8c41ab30ee077535c3fb3b10e9b3465f29f1cfecbf95a' 
  AND token = 'ufPjwP+NuoxVHHr8gJjneMCKEOu3wCfJS9Yun2DAtT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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