SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1377c1e8d8e36ae7d9589882c5aa2341165047e6fc84d9f42a9d665ff3bdafba' 
  AND token = 'KvywCWIFtJRKqQxG+xAk1IjH+3xxjorPaKMJCldjfsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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