SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f77ffa398a870e8db7de4382527ef5ba7660a5d71bf7ac7d6911c574624c358' 
  AND token = 'hBdCQ+V8igYTSX+ALX1Qa/L4mQ6v5qTLZP5nusc2/mk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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