SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da1580b89f85d28ff758477b3c602470a5a6f64deafda573cc54969cc09f603d' 
  AND token = 'jFdgiApNXIR8zaTjVAt+huZ1FdvMJSDFjUOlZe+cE7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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