SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1862859125f25487ef6ba87158fc65745ec778549b44afae56f77e89a44005c' 
  AND token = 'ACqfGyV97FIrxXlorvQlgu8U4psZPmAIF0pEzBMcMRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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