SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03ffc175cad103f201c11cf119ddce93bfefa781a2612048328154b1b98ff015' 
  AND token = 'XA3N8u6FHPIp6dcF8vRuMRGW2I/aG1ZyoBH3Fd/HfC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}