SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '563dfb7277df1347ea4ef5c8271a1cb73944db5afd806c548660b18099067c81' 
  AND token = 'ouAOpcFOES1jOsEsEY5m7U0hPRKN5g1tCawQ7EALf7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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