SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93584bf2cf38a883d9ca9f8da5048e133922ef4cb60b365c8dfdbace45843d50' 
  AND token = 'rimGDClc96+xzzJLN1EqEH4IhMpXKjPXclb34jRXgdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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