SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f4a5ff93508b4e086fa9ec27d624395a91d22ebaca77e0e9d8fa37df6ff754f' 
  AND token = 'hEPByf2Vdie0uRw3MEvhiMp9wzhLvbEb2uI4LLxgOTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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