SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1af9e244e6f933e9571bfd34eb3ddc277a992ed6e88b3c4230fbd551079ffd83' 
  AND token = 'fgQ6LEmEPYSI8tWQL56qqxMqULuI6KyOViggJZ6YqE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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