SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cc85d427cebe3675567c2b1500b53a5a30148a3a62c36fbc2551ddcab914535' 
  AND token = 'ShLOJEbkr2GqI1rgTnpbeNsZCHXDslxzwnqOLyWF+0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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