SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '967bc089373abd3e0fe232162c7902532f65a33d68cd6dbb5bab77eb842198a1' 
  AND token = '/osYRuCzfUgb0zEtBjIgcNVEibNLasbMCY/sDmPK28c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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