SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59546b48400590f227efeacf36f7d3c4c740516b2c94e1b86ffa23b1957bb9fd' 
  AND token = 'lfg5AL/DJ36qwhlh/YyPjav9XPQI1KSCVfjqIFfX27E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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