SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f58a1f2b8a09be3231f8dfa3548412c407fbf4c0f79869540c75a33885f60ca3' 
  AND token = '0flVvSomrBi/hal/T9UTyiG8TS/jJwRqxCqV5VQ5WCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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