SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c22d3cbc136167a1ec141e25faa4b49a096d13a757199b1ee4a1bf292a8886f1' 
  AND token = 'SK2aunjXnYQMdFZz73KAMygd9tICaAdHNHNwZISGCbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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