SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a1ca85c31532cc2c21a298dc7c900f585f678310c131941072108ba07e48ff1' 
  AND token = 'gJOBFX6P7Fc9BZm+VVUDQ5PS5/akF2P/hGSdpmgUJM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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