SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7315782682d7c94f5e7a29ebb88939e19a5643bb68b7a5ff90fa0207f49a1684' 
  AND token = 'AaJb4/UUmGrcqTS486BCebFNK2DZ/nW/xI9ZNCERBQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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