SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f8a87614bf6a2f157150c89183d8f39c719c67aeb268221415c4e686d7f5d58' 
  AND token = 'QgVMy7HlcOkwJqDL4YKUq53Pr+J6z+4vjiW/g2ilXVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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