SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8f2ac1415a264c58cab67db2ab99c42182459f79f03d3c1c55135f7e71a1368' 
  AND token = '+GquXvF5KOFFkx+vIgkgv9FTrZGk6Xy7U/KVcpiwUus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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