SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '614ac87ab498134de712f777bb80048e1e3ee3cfc0dc4cccf1b713a23b02d16e' 
  AND token = 'zhs1InuVeGz1SBILoQs3yMoC48DSw8fUMbpuQqGCVog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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