SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da775cc945844492fa574319a20b305956ae106b15a3fa73f7323960563dabeb' 
  AND token = 'pqjn7PDLUhNG5c3vsv8JuztsKnCKE2IgAEYEIpiBZTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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