SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56d2f33426d4bb03f5c9a5f327a06163cf91a4ed049609bbc0b2346ff77725a5' 
  AND token = 'ltaY1xmxXVW9gdxVAnyQHIWffUGEJPVdl3zKW/bZVPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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