SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef96dc884adfd1f1622ff89b0abfa957ad25b55b6c44c0c820e5500696648266' 
  AND token = 'vdLlXwrdJZssGGeAsJVyF1Gh9S77sG0h90+E650kMTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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