SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52aedf000f160815aba829e8e5e51524084bb1849e9b8975469713ed9eca3000' 
  AND token = '5YluWhwitwPn9kLEH39O4gKxbymCcakTz3X528xgvtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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