SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79ed071a00ee4725b07e060868bdc2a47d5d661afa07f35cab761d9eed509283' 
  AND token = 'pQAhjO7crub8alfw5pIH2oepq6ikq7KuSBxpN7Uc0ns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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