SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b8533eb2cfc7a1f961517c3a0d12f6f93d17fd9ea2713ce0c5f8d50b31a9dfe' 
  AND token = 't93s4QdDc/bBbpidDFNkzqTKgkmIFgNi3n3uBuZsPcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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