SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c56906e66a1fe047f87308b23501b73d277f8a454dd09556d98520815351a89' 
  AND token = 'hbLswga+c36uSEBihjemzcf2lYqe3ZtcyQqCoNRjIJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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