SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2960ef788f437b4342989759e771a0761b0e139165841fecbcb210612e834763' 
  AND token = '/MJ0tnn824SApRDyddWYbYfqW2HRk/k9WWtjb3q+4gc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}