SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c560fc41a0d4789adffaac23bbb70dccc4898253edf44fafb927a50972486d58' 
  AND token = 'LAAOr6+ibYqUObJKO4K45yVJavnXnhFoMLfiZVh3dLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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