SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4caecdaf018baabd39716ce89a457f3a0a9dab231fdf7e3728a84a1f671877aa' 
  AND token = 'jNiYfeUwa+0wGFRYeSP2HeNhLma9lXfm6TNtj6Ycf8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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