SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fdc388dc05a45d9d21775da6894b3cff50b274c876b4dd7dd1b4f0856d0ff7a' 
  AND token = 'B9pN/MxKZhebPC3VQrIh95I60YPJcqZqCWnPhVFYwQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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