SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77241a90e4fa8a289085996bfbf67753c689c087ef5875fe8e347097f0dd01c3' 
  AND token = 'y+pnJGVmDiTSZgfiw2+/lHJW/MgXCykKlB6aya60NiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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