SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb21196145dd3848f26684162cb33e896245b5a0e15f9dbf388b1c598dfd3735' 
  AND token = 'hVCr+qphYSEam6l0mIcef+9GaJUAWFdFeM0JvXOaYMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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