SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2adbb06765cc66fa9153189842f8bf6166d9ae2b5d851ba7b453ef6512d7f198' 
  AND token = 'TQ3z/5UsGnrYgPMM+08JL4XDfjFsuZbKLNy7IDEkYDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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