SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea780107b23357f36d459de9c1793009349560edb48fd293ca12788c84c55e42' 
  AND token = 'eYWiO8KHNr+LQ4g9vz8/w1fbSnhlNSi8J4hwJSHJG1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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