SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8189951f96f167da45e80ba5a6a809decd7657cf2f4b8c1e63da3470270d23aa' 
  AND token = '0tniripRvnfvKUsMHEyGzF+znjdoj0vJ5ChdjvIVSIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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